There are a number of agricultural operations to be performed at ends of rows on a field. Such rows are in the most cases arranged in parallel and the distances between the rows are equal or at least similar.
A first example of such an operation is to deposit and collect boxes into which workers put vegetables or fruit harvested from plants grown in the rows. Another example is maintenance of an irrigated field. Such fields can comprise parallel raised rows and parallel lower furrows between the rows. Plants are grown on the raised rows, while the water is allowed to flow in a number of the furrows for watering the plants. A common situation is to flow water between alternating raised rows to conserve water and prevent waterlogging. However, other arrangements can also be made. A head ditch provided at the end of the field and extending generally perpendicular to the rows and furrows contains water for the field and needs thus to be connected to those furrows into which water is to flow.
One method of controlling which furrow(s) are to have water flowing into them is to create dams between the head ditch and those furrows that are to be kept dry. The other furrows are, due to lack of a dam between them and the head ditch, connected to the head ditch and get watered. These dams are called rotobucks and produced with a dedicated type of implement (also called a rotobuck) that is pulled by a vehicle, usually a tractor, and scrapes ground material together when the vehicle is moving. The implement is triangular shaped with a point on each triangle tip that penetrates into the ground and builds up a mound of ground material along a curved edge of one side of the triangle, which will become the dam. A latch holds the tool in place as the vehicle pulls it around the field. When the latch is released, the tool rotates, depositing the ground material that has been built up along the curved edge of the triangle, and then rotating the tool to the next side, where another mound of ground material is built up for subsequent deposit.
In the prior art, the latch, which is hydraulically moved, is controlled manually by the operator of the tractor, by a suitable interface within the operator cabin. The position where, or the time when, to release the latch is critical to ensure that the dam is deposited in the proper location. Often, a second person is used to watch the position of the rotobuck device in the field and tell the tractor driver when to release the latch. When the correct position is missed, the operator or the second person needs to use a shovel to rebuild the dam at the correct location. Thus, manual control of the rotobuck device is a difficult and time consuming task. Additionally, the dams may need to be rebuilt every time it is necessary to go into the field with other devices, like sprayers, since they are normally destroyed or damaged by these other devices. This may happen several times during a growing season.
Automatically controlled arrangements for providing the dams are available, that steer the tractor along the head ditch, while software controls the implement to provide the dams. However, since these arrangements rely on a single spacing of the dams, a problem arises when the angle between the head ditch and the rows varies over a field, since this angle has an impact on the correct spacing between adjacent dams.
Since many fields are not completely rectangular in shape, especially at field ends, there is a need for a simple and reliable system for automatically performing agricultural operations on a field with parallel arranged rows having ends that are not all at the same angle to the head ditch.
It is an object of the present invention to provide a simple and reliable system for automatically performing agricultural operations on a field with parallel arranged rows having ends, such that the operations are automatically performed at desired locations related to the positions of the rows with respect to the head ditch.